Recovering resins from coal



. cedures.

Patented Dec. 51944 UNITED STATES PATENT ;OFFICE REoovEmNG RESINS FROMCOAL Adrlaan Nagelvoort, Salt'liake City, Utah No Drawing. ApplicationAugust 11, 1942,

Serial No. 454,463

2 Claims. (01. 2096)- coal.

Hard copal resins of the kauri type exist in impure form in certaincoals, notably in the upper, seams of Utah bituminous coal. resins arescattered throughout the coal in small lumps, streaks and lenticularmasses, of various sizes. The lumps vary in'color from light lemonyellow to deep red. Recovered in a pure condi- This invention relates torecovering resins from down the coal proper an undesirable degree.

' More specifically, I find that by grinding the The6 tion these resinsare useful in making oil varnish 10 and for similar purposes. They areinsoluble in many solvents, but, like the copals of commerce, they canbe run" and are afterwards soluble in drying oils, such as linseed oil.

In my cop'ending-application, Serial No. 368,-

' 737, flied December 5, 1940, for Recovering resins from coal of whichthis application is a contlnuation-in-part there. is disclosed andclaimed a method of recovering resins from coal, by a.- sinkand-floatprocedura making'use of the difference in true specific gravity betweenresins and coal:

and of freeing the resins of'asphalts and waxes by furthersink-andflioat steps. The product is useful in varnishes, and can befurther purified,

advantageously by the process of my application 26 Serial No. 432,087,filed February 23, 1942, entitled Purifying resins, to yield a resinproduct comparable in every respect with the best grade fossil copals ofcommerce.

The present invention is. concerned with improvements'in recoveringresins from coaLand especially in the initial stages of concentration;

The object is to simplify and cheapen the :pre-

liminary rough concentration and at the same time to handle the rawcoal. in such manner that its lump size is reduced as little aspossible, where-- by the resin-freed coal is kept in a condition morecommercially attractive than is powdered coal.

Treatment of resins by sink-'and-float, solvent. extraction and otherpurification methods re quires *that the resin be finely divided, so asto pass a 20-mesh screen for example. Hitherto the whole coal has beenground up to this size directly, prior to application of purificationpro- There are disadvantages in this, be-

, content of the coal.

flat lenses, streaks,

raw coal only to the extent that it passes say a one-inch-mesh screen,and then screening the coal, can the'nbe'grdund to treatment size, say

minus 20 mesh, conveniently in a rod mill. The coarse'coal lumps, muchof which are coarser than inch, are 'a valuable byproduct. Thisresin-freed coal can be used .in ordinary stokers, etc. and commands ahigher-price than raw coal of .the same size, because it is virtuallysootless.

In a specific example illustrative of one good mode of practicing theinvention, 1000 pounds of Utah coal containing 50 pounds of non-coalresinous matter, i. e. impure, resins associated with asphalts and awere crushed in a conventional coal crusher s as to pass a one-inchscreen.- The cr hed cl was now tumbled in a slightly incline I by 6inches diameter. Some reduction of the resin particle size occurred butthe coal proper V was not broken .down much. The tumbled coal wasscreened with a it, inch screen, through cause of excessive grindingcosts and because the resin-free coal is virtually in the form ofpowdered coal, which makes it a rather low-grade byproductdespite thefactthat it is a better coal than the raw coal by virtue of theelimination of the soot-forming resins. I I

The present invention is based on the discovery that by taking advantageof the physical form and size in which theresin occurs in the. coal, itis possible to take out of thecoal meat the same time theresin'inclusions are subwhich passed about '80 per cent of the totalresin,

or about 40 pounds. The screenings were broken in a rod mill to minus 20mesh size, and subjected to further treatment according to Theresin-freed coal had a sieve analysis as follows:

' Percent Above a inch.insize '15 Below inch insizer. 25

It was characterized by ifeedom from soot in combustion.

, From the foregoing it will be apparent'that my invention provides amethod of preliminary separation of resin from .coal whereby the:production of excessive coalfines is avoided and the treated coal is ofdesirable lump size, while chanically most of the resin, withoutbreaking stantially completely removed.

: ing cylinder, 3 feet long my acknowledged pending applications.

WhatIclalmlsrv 1. In recovering resins tromicoal in which the resinexists as discrete inclusions, the method which comprises breakingdown'the coal to a lump size only small enoughsc that, theresiningranules of substantially smaller average size than the lumps ofcoal, tumbling the brokendown coal to cause. the lumps to :rub eachother and dislodge the resin, mechanically separating -arelatively'smallsize traction consisting maln- 1y of resin granules anda relatively large size fraction consisting mainly 'of large coal lumps,

' and purifying the sepm'atedv resin granules;

. clusions are largely separatedifrom'the coal as v screen to separatethe smaller resin granules from the larger coal lumps, and purifying theseparate'd resin granules.

NAGELVOORT.

